package com.zhuojy.equity.mall.admin.web.security.component;

import java.io.IOException;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;

import com.zhuojy.equity.mall.admin.web.security.config.IgnoreUrlsConfig;
import lombok.RequiredArgsConstructor;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpMethod;
import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;
import org.springframework.stereotype.Component;
import org.springframework.util.AntPathMatcher;
import org.springframework.util.PathMatcher;

/**
 * 动态权限过滤器，用于实现基于路径的动态权限过滤
 */
@Component
@RequiredArgsConstructor
public class DynamicSecurityFilter extends AbstractSecurityInterceptor implements Filter {

	private final DynamicSecurityMetadataSource dynamicSecurityMetadataSource;

	private final IgnoreUrlsConfig ignoreUrlsConfig;

	@Autowired
	public void setMyAccessDecisionManager(DynamicAccessDecisionManager dynamicAccessDecisionManager) {
		super.setAccessDecisionManager(dynamicAccessDecisionManager);
	}

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {

	}

	@Override
	public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
			throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest) servletRequest;
		FilterInvocation fi = new FilterInvocation(servletRequest, servletResponse, filterChain);
		//OPTIONS请求直接放行
		if (request.getMethod().equals(HttpMethod.OPTIONS.toString())) {
			fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
			return;
		}
		//白名单请求直接放行
		PathMatcher pathMatcher = new AntPathMatcher();
		for (String path : ignoreUrlsConfig.getUrls()) {
			if (pathMatcher.match(path, request.getRequestURI())) {
				fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
				return;
			}
		}
		//此处会调用AccessDecisionManager中的decide方法进行鉴权操作
		InterceptorStatusToken token = super.beforeInvocation(fi);
		try {
			fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
		} finally {
			super.afterInvocation(token, null);
		}
	}

	@Override
	public void destroy() {
	}

	@Override
	public Class<?> getSecureObjectClass() {
		return FilterInvocation.class;
	}

	@Override
	public SecurityMetadataSource obtainSecurityMetadataSource() {
		return dynamicSecurityMetadataSource;
	}

}
